OBJECTIVE: To establish a screening model for females of reproductive age carrying Duchenne muscular dystrophy (DMD) variants based on a current community health examination platform. METHODS: A total of 61 870 participants were recruited between October 2017 and October 2019. Serum creatine kinase (CK) was measured with a Roche Cobasc 701/702 using an enzymatic rate method. Genetic testing was offered to those with a CK level of ≥ 200 U/L. For carriers of DMD variants, genetic counseling and follow up were provided. RESULTS: For the 61 870 females participating in the program, 1078 were found with raised serum CK (≥ 200 U/L), of which 618 (57.33%) accepted CK re-measurement after at least a two-week interval. One hundred and twenty cases were found with sustained serum CK elevation, of which 6 were confirmed to be definite DMD carriers regardless of family history. Genetic testing was provided to 33 females with a family history for DMD, and 13 were determined as definite carriers. An affected fetus was detected by prenatal diagnosis. After genetic counseling, the parents had opted induced abortion. CONCLUSION Large-scale DMD carrier screening through a three-step approach based on the current community health examination platform is both feasible and cost effective.
Female ; Genetic Carrier Screening ; Genetic Counseling ; Genetic Testing ; Humans ; Muscular Dystrophy, Duchenne/genetics* ; Pregnancy ; Prenatal Diagnosis

Child, Preschool ; Flow Cytometry ; methods ; Genetic Carrier Screening ; Granulomatous Disease, Chronic ; diagnosis ; genetics ; Humans ; Infant ; Male

OBJECTIVE: To explore the effect of chromosomal translocations on the composition of embryonic chromosomes and its mechanism. METHODS: For 52 couples with one partner carrying a chromosomal translocation, results of next generation sequencing of all embryos derived from 61 cycles were divided into different groups based on the type of translocations, gender of the carrier, and maternal age. Effect of parental chromosomal translocations on the composition of embryonic chromosomes of each group was analyzed. RESULTS: A significant difference was found between carriers of reciprocal and Robertsonian translocations in terms of proportion of abnormal embryos and structurally normal chromosomes (63.3% vs. 27.5%, and 1.1% vs. 0.3%, respectively). Compared with male carriers, there was an increase in the rate of abnormalities for female carriers (67.2% vs. 58.3% for reciprocal translocations, and 45.5% vs. 13.8% for Robertsonian translocations). The risk for chromosomal abnormality also increased with the maternal age. No significant difference was found in the proportion of abnormal embryos between carriers divided by involvement of acrocentric chromosomes or terminal chromosomal breakpoints. CONCLUSION The types of parental translocation, gender of carrier, maternal age, and interchromosomal effect have certain effect on the composition of embryonic chromosomes.
Chromosomes, Human ; genetics ; Female ; Genetic Carrier Screening ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Maternal Age ; Pregnancy ; Preimplantation Diagnosis ; Translocation, Genetic

OBJECTIVETo establish a simple, rapid genetic diagnostic system for haemophilia B.

METHODSThe polymorphisms of eight STR loci in 87 normal persons and 8 haemophilia B families were assayed by PCR and genescan, and the linkage relations were analysed.

RESULTSSix of the eight STR loci can provide genetic information for haemophilia B, and the heterozygosity is 0.50 approximately 0.83, PIC 0.39 approximately 0.80, and DP 0.66 approximately 0.94.

CONCLUSIONCombination of multiple STR loci analysis could be effective method for genetic diagnosis of haemophilia B.

Female ; Genetic Carrier Screening ; methods ; Genetic Linkage ; Genetic Predisposition to Disease ; Hemophilia B ; diagnosis ; genetics ; Humans ; Male ; Microsatellite Repeats ; genetics ; Pedigree ; Polymorphism, Genetic

This study was aimed to investigate the prevalence and genotype distribution of heterozygotes in beta-thalassemia combining deletional alpha-thalassemia by using molecular detection and haematological methods. Three common deletions of alpha-thalassemia were detected by using gap-PCR. The mutations of beta-thalassemia were identified by using PCR with reverse dot blot hybridization. The routine analysis of blood cells was carried out. The results indicated that 15 cases from the 81 beta-thalassemia traits were found to be the compound heterozygosity for beta-thalassemia and alpha-thalassemia with 9 different types of gene defects with 18.52% detection rate. There were 6 cases (7.41%) of beta-thalassemia heterozygote combining alpha-thalassemia-1 gene (--(SEA)/alphaalpha), 8 cases (9.88%) combining with alpha-thalassemia-2 gene including 6 (7.41%) right ward deletion (-alpha(3.7)/alphaalpha) and 2 (2.47%) left ward deletion (-alpha(4.2)/alphaalpha), and 1 case (1.23%) combining deletional HbH gene (--(SEA)/-alpha(3.7)). No significant differences were found between beta-thalassemia heterozygotes combining deletional alpha-thalassemia and pure beta-thalassemia in all RBC parameters. It is concluded that the incidence of beta-thalassemia heterozygotes combining with deletional alpha-thalassemia is frequent in Wuzhou city. The hematological analysis can not give specificity for diagnosing these dual heterozygotes. Gap-PCR as a routine method for thalassemia screening has the advantages in reducing the possibility of failing to detect the combining heterozygosity for beta-thalassemia and alpha-thalassemia. It is more useful for genetic counselling and prenatal diagnosis of this disease.
Adolescent ; Adult ; Female ; Gene Deletion ; Genetic Carrier Screening ; methods ; Genotype ; Heterozygote ; Humans ; Male ; alpha-Thalassemia ; genetics ; beta-Thalassemia ; genetics

OBJECTIVETo establish a fast and simple genetic diagnosis technique based on a reliable, short tandem repeat (STR) genetic marker system for the detection of hemophilia A carriers in Guangxi, China.

METHODSFluorescent PCR and capillary electrophoresis were used for allele genotyping at three intragenic/extragenic STR loci (F8Int13, DXS1073, and DXS9901) of FVIII gene in the members of 10 hemophilia A families in Guangxi, so as to evaluate the diagnostic efficiency of the STR genetic marker system for detection of hemophilia A carriers. Then the STR genetic marker system was used to detect hemophilia A carriers among examinees.

RESULTSIn the 10 hemophilia A families, 11 confirmed female carriers had the same allele fragment lengths at the three STR loci (F8Int13, DXS1073, and DXS9901) as the probands. Of the 8 females examined, 5 had allele fragments at the three STR loci (F8Int13, DXS1073, and DXS9901) which were identical to those of the probands, and thus they were diagnosed as hemophilia A carriers.

CONCLUSIONSGenetic analysis at the three STR loci (F8Int13, DXS1073, and DXS9901) can be used to detect hemophilia A carriers rapidly and provide reliable basis for prenatal diagnosis of hemophilia A.

Adolescent ; Adult ; Child ; Child, Preschool ; China ; Female ; Genetic Carrier Screening ; Genotype ; Hemophilia A ; diagnosis ; genetics ; Humans ; Male ; Microsatellite Repeats ; Middle Aged

OBJECTIVETo screen and detect the female carriers from the DMD/BMD family members for prenatal or preimplantation genetic diagnosis.

METHODSFor the detection of DMD/BMD carriers from 27 family members in 4 families, PCR to five microsatellite markers(located in 5' terminus and intron 44, 45, 49, 50) and analysis of the short tandem repeat(STR) sequence polymorphism with the use of genescan were implemented.

RESULTSSix of the 17 female members were obligate DMD gene carriers according to the haplotype analysis of the results of the genescan, which conformed with the pedigree analysis. Besides, the authors detected five carriers and five normal females in these families with the use of the haplotype analysis only. The most polymorphic locus was STR 49, and the least was STR 50.

CONCLUSIONThe STR haploid linkage analysis using (CA)n repeats within the human dystrophin gene is a rapid,accurate, objective method and is well suited for routine use in clinical laboratories engaged in DMD/BMD linkage analysis for the detection of carrier.

Female ; Genetic Carrier Screening ; Humans ; Male ; Microsatellite Repeats ; Muscular Dystrophy, Duchenne ; genetics ; Polymerase Chain Reaction ; Tandem Repeat Sequences

OBJECTIVETo establish an effective laboratory examination system for carrier detection and prenatal diagnosis of haemophilia Alpha(HA) with a variety of molecular biological methods which are simple,rapid and easy to use.

METHODSDetection of inversion involving intron 22 in the FVIII gene was completed by long distance polymerase chain reaction (PCR) and linkage analysis was performed by using several genetic polymorphisms including an intragenic Bcl I RFLP, 2 STRs and an extragenic St14 VNTR.

RESULTSIntron 22 inversion was observed in 10 out of the 21 (47.6%) pedigrees examined. Prenatal diagnosis was completed in 3 pedigrees. A further combination of the four intragenic and extragenic polymorphic loci gave an informative rate of 94.7%.

CONCLUSIONSFemale relatives in HA families with inversion can be detected with direct diagnostic procedure. The application of long distance PCR makes the detection much more simple and rapid. For families without inversions,it is easier and more cost-effective to undertake linkage analysis of genetic polymorphism based on PCR.

Chromosome Inversion ; Female ; Genetic Carrier Screening ; Hemophilia A ; diagnosis ; genetics ; Humans ; Introns ; Minisatellite Repeats ; Polymorphism, Restriction Fragment Length ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo report the analysis of a rare beta-thalassemia ternary heterozygote [+40 to +43(-AAAC)*CD41/42(-TTCT)*IVS-2-654] causing beta-thalassemia major in a Chinese.

METHODSUsing PCR-ASO probe hybridization analysis to scan 17 known types of beta-thalassemia mutations, and gene cloning and DNA sequencing to identify the underlying causative mutation.

RESULTSReverse dot blot (RDB) analysis showed that the patient's beta-globin gene had three mutations: +40 to +43(-AAAC), CD41/42(-TCTT) and IVS-2-654(C to T). Beta-globin gene cloning and sequencing proved that, the two deletions of +40 to +43(-AAAC) and CD41/42(-TCTT) co-existed on the same chromosome, and the other homologous chromosome had an IVS-2-654 (C to T) mutation. So the patient is a compound heterozygote of [+40 to +43(-AAAC)*CD41/42 (-TCTT)]/IVS-2-654 (C to T) leading to beta-thalassemia major.

CONCLUSIONThe triple mutation of [+40 to +43(-AAAC)*CD41/42(-TCTT)/N] is a new genotype of beta-thalassemia in Chinese.

Codon ; DNA Mutational Analysis ; Female ; Genetic Carrier Screening ; Haplotypes ; Heterozygote ; Humans ; Mutation ; Nucleic Acid Hybridization ; beta-Thalassemia ; genetics

OBJECTIVETo identify the molecular etiopathogenesis for a non-syndromic hearing loss patient.

METHODSThe core family, consists of the patient and his parents, was recruited. Genomic DNA was extracted from peripheral blood. Mutation analysis was carried out by SNaPshot and next-generation sequencing technology. Mutations in SLC26A4 gene were verified by polymerase chain reaction and direct sequencing.

RESULTSCompound heterozygous mutations p.V306GfsX24 and p.P516PfsX11 in SLC26A4 gene were detected in the patient, heterozygous mutation p.V306GfsX24 was detected in the father, heterozygous mutation p.P516PfsX11 was detected in the mother.

CONCLUSIONSCompound heterozygous mutations p.V306GfsX24 and p.P516PfsX11 contributed to patient's hearing loss. Next-generation sequencing technology is a useful tool for detecting de novo mutations of deafness genes, and is suitable for clinical application.

Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; DNA Mutational Analysis ; Deafness ; genetics ; Female ; Genetic Carrier Screening ; Genetic Testing ; Humans ; Male ; Membrane Transport Proteins ; genetics ; Mutation ; Pedigree